Priming system for internal-combustion engines



G. HONOLD AND A. KRAUSS. PRIMING SYSTEM FOR INTERNALCOMBUSTION ENGINES.

APPLICATION FILED APR. 13. 1918.

1,327,430. Patentgd Jan. 6, 1920. r

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By ATTORNEY? UNITED STATES PATENT OFFICE.

GOTTLOB I-IONOLD, F STUTTGART, AND ADOLF KRAUSS, OF CANNSTATT, GERMANY,

ASSIGNORS, BY MESNE ASSIGNMENTS, TO AMERICAN BOSCH MAGNETO CORPORA- TION,'0F NEW YORK, N. Y., A CORPORATION OF-NEW YORK.

'PRIMING SYSTEM FOR INTERNAL-COMBUSTION ENGINES.

Application filed April s, 1918. Serial No. 228,492.

To'all whom it may concern:

Be it known that we, GOTTLOB HONOLD,L subject of the German Emperor, residing at and whose post-ofiice address is Stuttgart Militarstrasse 4, Germany, and ADoLr KRAnss, a subject of the German Emperor,

- residing at and Whose post-office address is Cannstatt, Bryestrasse 8, Germany, have invented certain new and useful Improvements in Priming Systems for Internal-Combustion Engines; and We do hereby declare the following to be a full, clear, and exact description of the invention, such'as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to a pump for introducing air and fuel into the cylinders of internal combustion engines and more especiall of such engines as are started by hand or by aid of a starting motor. The object of our invention is to facilitate the starting-of such machines. As is well known the usual hand crank does not produce a high velocity of the pistons. Even in case a starting motor is used the starting-velocity is comparatively low; for such amotor must be as small as possible inorder to keep the weight of the motor and the battery to be carried by the car as well asthe costof such motor as low as possible. Now the low starting velocity has the disadvantage that the c'arbureter furnishes a mixture of low igniting capacity and the magneto a less energetic igniting spark. As long as'the internal combustion motor is warm, it will start easily notwithstanding these circumstances; however, when the motor is cold as will generally be the case during the winter after a longer stoppage, then the mixture produced with a low starting velocity cannot be ignited by the spark or will require :a long starting time in order to be ignited.

This disadvantage is minimized in accordance with the present invention by means of a priming system containing a pump connected on one side with the float chamberof the carbure'ter and on the other side with the fuel inlet of the engine, the piston of the pump preferably containing an air valve, and the conduit connecting the cylin der of the pump with the engine inlet preferably containing a valve which establishes an air vent for the conduit when the pump is not operated, and closes the air vent when Specification of Letters Patent.

7 Patented Jan. 6, 1920.

the pump is operated, whereby a measured quantity of fuel in the pump is forced into the engine inlet in an atomized condition preliminarily to starting the engine by means of the hand 'crank'or the starting motor.

In the accompanying drawings, Figure 1 represents diagrammatically a priming system according to the invention, and Fig. 2 represents in vertical section a modified formof valve dr'awnto alargerscale.

Referring to Fig. 1, a is the float-chamber of the oarburet'er, 0' is the cylinder of the prlmlng pump and forming a measuring tube, 6 is a pipe connecting the float "(Sham her with the cylinder. is the ball of a check valve arranged in the pipe '6 and adapted to "move freely within the valve casmg 6 so that whenever the level of the fuel within the carbureter is higher than in the measuring "tube, the ball cl is pressed by the liquid passing from chamber a to the "tube 10 to theright into the openrposition. Thepiston of the priming pump is provided with a ball valve 9 so arranged that when the piston is moved downwardly,the ball closes the inlet openingh, and when the piston is moved upwardly, air'en'ters the cylinder below the piston through the openingsc', hand is. Frointhe lower part of cylinder 0 a pipe Z leads to the double-faced check valve on provided with a balla adapted to move between the seats 0' and '19. Seat 7'9 is'connected with the open air, and seat 0 with the spray tube g passing through nozzle 1" and ending in the inlet pipe '8 of the motor. The float chamber of the carbureter is connectedby a separate conduit 64 with the inlet pipe s, the slide 6" being opened when the pump is operated to prime the engine, and closing the pipe t when the engine is running in normal operation. I Y i Theoperationof-thisdevice is as follows: Whenever piston o'f the air pump is presseddownward, ballg will close opening It andjthe air within cylinder e is pressed down'uponthe liquid containedin said-cylinder. At the same-time the check valve (Z closes the pipe'bleading to the carburetor a. Iii-consequence thereof the petrol is pressed from the pump cylinder or measuring tube into pipe Z'and exerts a pressure uponjthe columnof air contained within said'pipe,

Now this currentof air and of the petrol fodlowing it has a high velocity, and since the pipe Z and seat p have a small section, the air and petrol currents will, on account of the arrangement of the ball a in its casing, act against the ball to move it from seat 0 to seat p, so that this valve closes the connection with the free air and opens the spray tube 9. Now the petrol flows through seat 0 into. the spray tube 9 and is carried in a strong jet into the engine inlet 8 where it is mixed with the'air sucked in by the motor through the air pipe t, the slide 6 being open as shown in dotted lines in Fig. 1. When the pipes Z and g are only partially filled with liquid, the quantity of air passed over from tube 0 will flow with energy through the remaining petrol and will carry it into the engine inlet under a vigorous spraying action. As a great excess of air follows, also the particles of petrol adhering to the walls of the pipes are carried along by the air almost completely, thus causing a petrol spray to be produced in the engine inlet. Owing to this energetic spraying of the petrol its mixture with air and the ignitin capacity of this mixture is rendered as perfect as pos sible.

After the piston f has reached its lowermost position, it is pulled upwardly, the ball 9 immediately effecting the connection with the free air so that no vacuum is generated within the measuring tube. At the same time ball a of the double-faced check valve will, owing to the flow in the pipe Z being stopped, fall back upon seat 0 and will thereby place pipe Z under atmospheric pressure, so that the level of the liquid in tube 0 will at once be equal to the level in the carburetor, where the liquid is constantly kept at the same level in a well known man'- ner. No disturbance of this automatic adjustment from the motor driven with low velocity by the hand crank or the. starting motor can arise, as ball a of the check valve closes the spray tube against the vacuum created in the engine inlet 8. The quantity of air superposed on the quantity of petrol within the measuring tube is predetermined by the length of the path of the piston f; it is preferably made 'two or three times bigger so that for a given level in the carbureter the length of the measuring tube is predetermined.

The connection between the pressure valve m and the free air by aid of tube 39 is provided for thereason that an ordinary spring actuated pressure valve would impair the efliciency of the whole device for the fol lowing reasons:

1. .The spring would have tobe strong enough to prevent the pressure valve from being opened by the force of the suction created by the motor running at full speed as the motor must be prevented by all means from sucking in uncontrollable quantities of petrol from the float-chamber by going around the carbureter. Therefore such a pressure valve spring should be able to exert a rather strong pressure, but in this case the power to be exerted upon the piston would of necessity be far greater and the tightening .of the piston would have to be far stronger thus causing the pump to be far less easily handled.

2-. A check valve being placed under the pressure of a strong spring will, during the pressure stroke of the pump, open only a small section and will therefore throttle the supply of the petrol and air mixture. In consequence thereof a diminution of pressure will take place in the valve and this latter will act as a sprayer. This however will destroy the correct spraying effect, as in this case the mixture is sprayed into the tube Q instead of being merely sprayed into the mixture tube at the nozzle 9". Therefore a spring-actuated pressure valve causes the spraying operation to take place at a wrong place, that is to say within the interior of the sprayer tube instead of in the nozzle.

3. If an ordinary pressure valve gets loose the motor will suck in petrol from the float chamber, the ordinary pressure valve having only a backward connection with the pump cylinder (through pipe Z). Such a sucking in of uncontrollable quantities of petrol cannot be allowed.

All these drawbacks are avoided by arranging the pressure valve as described, said valve opening the entire section of the passage to the spray tube with the greatest facility.

As at the beginning of the pressure stroke the current passing into the free air immediately will press the valve down upon its seat and said valve will open the spraying pipe completely, the valve does not oppose any resistance to speak of to the handling of the pump, and in consequence thereof, the piston need be rendered far less tight and can be handled much easier and more comfortably than in the case of a spring-actuated pressure valve.

As the valve will open the full section, the throttling of the mixture and an undesired spraying within the. pipe is prevented. The current of petrol and air can pass freely through the spray pipe on to the nozzle and here only the diminution of pressure takes place which causes the spraying to be effected. Therefore the use of a suitable valve allows of obtaining the right spraying in the mixture tube and owing to this auxiliary atomization the motor will start easily.

As the pressure valve chamber is connected duringthenormal position of the valve upon thelower seat 0 through air pipe 79 with the free air, in case that the valve should get loose, the'motor will merely suck 7 in some air from the atmosphere. The harm done in this case is far less important than in the case of petrol being sucked in from the float-chamber as is the case with a spring-actuated pressure valve. 7

With the modification described above, if a very slow movement is given to the piston, it may happen that the current of air passing through the air pipe of the pressure valve does not'suffice to throw the ball of the valve upon its seat. By slowly pressing the piston farther down the petrol and the air would in this case pass through the pipe into the atmosphere and the motor would not be started. Although one may assume in general that the operator will press the piston down quickly, thus avoiding the danger mentioned, it is preferable to provide for the case of a too slow handling of the pump.

This can be eflected by providing the valve body of the pressure valve m with a piston easily moving within the pipe connecting the valve casing with the outer air and having the shape of a cylinder as shown in Fig. 2. Here n is theplug of the pres-, sure valve having the form of a double-cone connected by a rod with a little piston a movable within a small cylinder 2: provided with openings connecting its interior with the free air. The cylinder 1) replaces the air passage p of the modification shown in Fig. 1. The piston to can move with some play within the cylinder 41.

It is easy to see that even at a very low velocity of the piston f either the escaping air or the petrol following it will cause piston u to be lifted with certainty, until valve n is seated upon its upper seat. As piston u can move within cylinder 1) with some play, the movability of valve nis not impaired.

In the embodiments represented in the drawings the spray pipe leading to the engine inlet forms the pressure channel between the pump and the valve n, it is how'- ever feasible to arrange a special pipe leading from the air chamber of the measuring tube or pump to the valve, said pipe effecting a connection in such a way that at the beginning of the spraying movement the valve is caused by the air jet escaping from the air pipe 19' to pass from the lower to the upper seat.

We claim 1. In a priming-system for internal'combustion engines having a fuel inlet and a the pump a measured supply of fuel from the carbureter and air from the atmosphere and which, when the pump is operated, closes off the pump from the carbureter and the atmosphere and conducts the measured quantity of fuel and air to the engine inlet in the form of a spray.

2. In a priming system for internal com bustion engines having a fuel inlet and a carbureter, a fuel pump connected between the engine inlet and the fuel float chamber 3. In a priming system for internal combustion engines having a fuel inlet and a carbureter, a fuel pump connected between the engine inlet and the fuel float chamber of the carbureter, a valve in the'connection between the pump and the fuel float chamher, and a three way valve in the connection between the pump and the engine inlet comprising a piston loosely fitting in a cylinder and carrying a plug which, when the pump is not operated, closes off the engine inlet and vents the pump to the atmosphere, and which, when the pump is operated, closes the vent to the atmosphere and opens the engine inlet to the pump to conduct a measured quantity of fuel and air from the pump into the engine inlet in the form of a spray.

4:. In a priming system for internal combustion engines having a fuel inlet and. a carbureter, a fuel pump having a cylinder and a piston with an air valve, a conduit connecting the cylinder with the fuel float chamber of the carbureter, a conduit connecting the cylinder with the engine inlet, valves in said conduits which, when the pump is not operated, establish communication between one side of the cylinder and the fuel float chamber and between the other side of the cylinder and the atmosphere to maintain a measured supply of fuel and air in the cylinder, and when the pump is operated, interrupt communication between the cylinder and fuel float chamber and substitute for the communication between the cylinder and the atmosphere a communication be tween the cylinder and the engine inlet so that the measured quantity of fuel and air passes into the engine inlet in the form of a spray.

In testimony whereof we aflix our signatures, in presence of two witnesses.

I GOTTLOB HONO'LD.

ADOLF KRAUSS. itnesses: PAUL WOLFAST,

ADOLF LEBBERS. 

